Feb 2024, The response for the initial pulse and sequencer boards has been better then expected, the Demand for the older Miller 250DX units has also been heavy. So, I decided yes I will make some boards for the older units that take the Discontinued Miller Part Numbers  190734 and 190738. If You need Boards For the Newer Miller 250DX See The Original Miller 250DX Pulse Sequencer Build Post.

Decisions, On the Discontinued Miller 250DX Tig Welder PN: 190734 (Pulse) & 190738 (Sequencer) Boards.

Initially, my plan was to locate an older 250DX locally, either by purchasing one from the development funds or finding someone willing to allow me to remove the cover and take the measurements. However, the few individuals I approached who owned one were unhelpful, prompting me to continue my search for a parts unit.

On 02/19, I successfully located and ordered a New Old Stock Front Plate Miller 204776 for the older legacy Miller 250DX. This acquisition allows me to obtain the necessary measurements promptly, facilitating a test fit for the project sooner than anticipated. Upon its arrival, I will promptly extract the measurements, conduct a 3D print test fit, and proceed to manufacture a set of boards. I have made the decision to create a separate board set rather than attempting to incorporate two layouts on a single board.

I have confirmed via the (Miller Technical Manual TM-359G) that the pin outs for Pulser P/N:190734 and Sequencer P/N:190738 are the same even though the location of the connectors on the welders main board are located horizontally on the side of the main board vs the bottom.

02/22 The Front Plate for the Older 250DX Has Arrived this was Very Hard to find but it is new old stock.
Miller 250DX Legacy Face Plate For Making 190734 Pulse and 190738 Sequencer Replacement Boards
Unboxing Video of the Miller 250DX Face plate.

Took some measurements and did the layout for the sequencer nailed it except for 1 LED needs small adjustment.

Have both the pulse and sequencer drawn up. I may 3d print a model or I may just go with it on a small lot.

Immediately I Drew Modeled Up the Boards using the V2.0 Circuitry.

I used the Prusa and 3D Printed a Model to Test Fit the 190734 Pulse Board
Miller 250DX 190734 Pulse Board 3D Model Printed
Test Fit was Like a Glove… I Have my Pots at 7.60mm on the busing so yes they are very snug in the 7.62mm holes. I have noticed on the first beta boards that there are some variation in the tolerance on the metal stamping form welder to welder so a snug fit here = accurate centers of the Potentiometers. This will give about .25 mm each side of the Potentiometer for any pcb mfg and parts errors and stamping variance form machine to machine pots.
Miller 250DX 190734 Pulse Board 3D Printed Model Test Fit
Made the 3D Printed a Model to Test Fit the 190738 Sequence Board
Miller 250DX 190738 Sequencer Board 3D Model Printed
Test Fit of the Sequencer Board In to the Front Plate, Perfect Fit!
Miller 250DX 190738 Sequencer Board 3D Printed Model Test Fit
Here are the Very Crude Models!!

Both Installed

I will order a few Circuit Boards on my next PCB Order. When they arrive I will assemble a set and hook them up to my machine and use the scope and check signal quality if good I will assemble a few for the people that are one the wait list.

Boards Have been Ordered and Approved By The Board Manufacture and are In are Production As Of Feb 27th 2024 ETA March 5th or 6th 2024.

February 28th 2024 Production is more then 1/2 Way Prob Arrive Before the Parts to Assemble them.

Finished… And Delivered..

Unboxing Video

Miller Syncrowave 250DX Pulse 190734 Sequencer 190738 Boards Unboxed Its a Stack Of Them.

V2.0L (L Stands For Legacy) These Boards Will be the Final Revision For Retail Sale, They Look Do Nice!

Currently, I am awaiting the delivery of my Potentiometers. Regrettably, the seller initially delayed the shipment by a week. Shortly thereafter, they furnished tracking information, only to inform me a few days later that the initial shipment had been canceled. Nevertheless, they assured me they had addressed the issue and would dispatch the items through UPS, promising a new tracking number shortly. I remain hopeful that the updated tracking information will be available soon. In the interim, I successfully obtained a handful of Potentiometers, sufficient for testing the fit of the boards to the front plate.

And they Fit Nicely!! Whooo Hooo!!! Center Pots are Perfect Edge pots are about .125mm off (About 0.005″) but that is the pot and manufacture tolerance and well with in the .31 mm I have available. Hard to take a photo without a third arm. I will stand it up and make a video showing clearance.

I have assembled a set and the electrical Tests have Passed!

Assembly has Started as of March 9th and the first batch of V2.0 and V2.0L and is almost ready, So Anyone that has messaged me Via text, e-mail, facebook, and is on the wish list will have first dibs I have just enough parts to cover all of you. I have already send out e-mails asking for name, address, and e-mail so i can send invoice. Please respond by the 15th of march. 

V2.0L Boards (L Stands For Legacy) Pricing Coming Soon. Expect about 1/2 of millers price current pulser and sequencer board pricing.
Pricing 03/05/2024 These Will Most Likely Be Priced the Same As The V2.0 Boards or Slightly a Bit More. The First 10 Will be sold as pairs only.

RL-190734 Pulse Board $???

RL-190738 Sequencer Board $???

V2.0L Combo  RL-190734 & RL-190738 Boards $560 + $15.00 Shipping (3 Available 03/23) More Soon.

03/23 Everyone on the wish list was contacted and whoever replied received an invoice for the first batch. Of the invoices I sent out 3 invoices have Expired so I am making them boards available to the public. I have added a buy now below, or you can message me at 360 –9 7 5– 3165 and I will be happy to send you an invoice if an invoice is required. I have them also listed on ebay but price will be higher due to ebays 18% cut. Next batch will be available 1st or 2nd week of April. A Delivery Signature is Required on all orders over $300. 


I Hope by the time the boards and components come in est 12th to 24th of march of I will have a shopping cart installed on the blog here for ease of ordering.

RL-190734 Pulse Board will Replace Miller Part Numbers 190734 Flat Face 250DX Machines (Only)
RL-190738 Sequencer Board will Replace Miller Part Numbers 190739 Flat Face 250DX Machines (Only)

The RL-190734 and RL-190738 exclusively function with Serial Numbers starting from LA349426 to approximately October 2009 for 250DX Models. In the case of an older style flat-face 250DX towards the conclusion of the production cycle, it’s possible that your machine may have a newer model serial number. In such instances, it is advisable to refer to the Stock Number to obtain the appropriate manual.

03/23/2024 Customer Installed Photos (Hope i get more to show)

To determine the pulse and sequencer board required for your machine, begin by utilizing your Serial Number. Locate the manual for your welder at https://www.millerwelds.com/support/manuals-and-parts/ and download the Owners and/or Parts manual. Conduct a search for PC2 and PC3 to identify the Part Number specific to your machine.

For shipping within the US, there will be a flat rate of $15.00 for insured mail. Payment options include Cash if local, Checks, Money Orders, Cash App, or credit card payments. (Check, Money order, Cash/ Cash app Payments 3% Discount)

You can Call Me or Leave a Text Message 360 –9 7 5– 3165 Text Message are Best. (This is a public facing number calls and text message only that means no photos or media) if you wish to send photos or medial I will text you a different number or you can e-mail them.

Last Updated on March 24, 2024 by Steven Rhine

One thought on “Discontinued Miller 250DX Tig Welder PN: 190734 (Pulse) & 190738 (Sequencer) Boards”

Comments are closed.